1. Field of the Invention
This invention relates to fluid handling processes and apparatus. More particularly, this invention relates to new methods and apparatus for enclosing and mounting fluidic oscillators or inserts so as to improve their performance.
2. Description of the Related Art
Fluidic inserts or oscillators are well known for their ability to provide a wide range of distinctive liquid sprays. The distinctiveness of these sprays is due to the fact that they are characterized by being oscillatory in nature, as compared to the relatively steady state flows that are emitted from standard spray nozzles.
The flow patterns produced by the liquid emitted from a typical fluidic oscillator may be considered to be an essentially temporally varying flow of a liquid jet or spray that issues from the oscillator into a surrounding gaseous environment and breaks into droplets which are distributed primarily transversely (thus, we speak of their flow patterns as being “two-dimensional and planar”) so that the resulting spray is said to be characterized by a prescribed “fan angle” and “thickness” (see FIGS. 1 and 11 in the previously cited and related USPPN 2006/0108442 for the terminology and coordinate system previously introduced and being used herein to discuss the unsteady, oscillating flow of the liquid droplets from a fluidic oscillator (e.g., in FIG. 11: oscillating at a prescribed frequency in the x-y plane so as to create the horizontal fan angle, φ, and a rate of spread angle, θ, in the x-z plane which we define as the spray's “thickness”)). Such spray patterns may be described by the definable characteristics of their droplets (e.g., the volume flow rate of the spray, the spray's area of coverage, the spatial distribution of droplets in planes perpendicular to the direction of flow of the spray and at various distances in front of the oscillator's outlet, the average droplet velocities, the average size of the droplets, and the frequency at which the droplets impact on an obstacle in the path of the spray).
A fluidic insert is generally thought of as a thin, rectangular member that is molded or fabricated from plastic and has an especially-designed, liquid flow channel (i.e., fluidic circuit) fabricated into its boundary surface (assuming that this fluidic insert is of the standard type that is to be inserted into the cavity of a housing whose inner walls are configured to form a liquid-tight seal around the insert and form an outside wall for the insert's boundary surface which contains the especially designed flow channel).
There are many well known designs of fluidic circuits that are suitable for use with such fluidic inserts. Many of these have some common features, including: (a) at least one power nozzle configured to greatly accelerate the movement of the liquid that flows under pressure through the insert so that it separates from the walls downstream of the power nozzle so as to form an essentially “free” jet downstream of the power nozzle, (b) an interaction chamber through which the liquid flows and in which the flow phenomena is initiated that will eventually lead to the spray from the insert being of an oscillating nature, (c) an liquid inlet, (d) a pathway that connects the inlet and the power nozzle/s, (e) an outlet or throat from which the liquid sprays from the insert, and (f) an expansion section downstream of the throat.
Examples of fluidic circuits may be found in many patents, including the present Assignee's U.S. Pat. Nos. 3,563,462 (Bauer), 4,052,002 (Stouffer & Bray), 4,151,955 (Stouffer), 4,157,161 (Bauer), 4,231,519 (Stouffer), which was reissued as RE 33,158, U.S. Pat. Nos. 4,508,267 (Stouffer), 5,035,361 (Stouffer), 5,213,269 (Srinath), 5,971,301 (Stouffer), 6,186,409 (Srinath) 6,253,782 (Raghu), 7,267,290 (Gopalan & Russell), 7,472,848 (Gopalan & Russell), 7,478,764 (Gopalan), and 7,651,036 (Gopalan).
Despite much prior art relating to the development of fluidic circuits, the nature of the housings or enclosures that surround fluidic inserts and the methods for mounting fluidic inserts had, until recently, changed only slowly over the years. Representative examples of the housings for fluidic inserts and the methods for mounting them are described in U.S. Pat. Nos. 5,845,845, 6,062,491, 6,464,150, 7,014,131, and 7,111,800 and in USPPNs 2004/0227021, 2006/0108442 and 2006/0043110.
As fluidic inserts have continued to be used in more types of applications, the opportunity has arisen to re-examine and improve upon the design of their housings and mounting methods as a way to improve upon the overall spraying performance of the nozzle assemblies, etc. which use fluidic inserts or oscillators. This is especially important in the creation of fully “three-dimensional spray patterns” (as opposed to the primarily two-dimensional spray patterns that are yielded by present fluidic spray devices).
Commercial three-dimensional, liquid sprays are usually produced in only a few ways: (a) a swirl nozzle, that produces a circular spray pattern which can be full of small droplets or hollow due to the nozzle's high rotational speeds, and (b) shearing the spray by means of a “spoon” type nozzle (mostly used in the headlamp industry) which also typically yields small, low velocity (lacking in power) droplets. In general, these spray devices do not yield the often desired “powerful (high velocity, larger size droplets), three-dimensional” sprays needed for assorted “cleaning on impact” applications. Further improvements are needed in the creation of “powerful, three-dimensional” liquid spray devices.
3. Objects and Advantages
There has been summarized above, rather broadly, the prior art that is related to the present invention in order that the context of the present invention may be better understood and appreciated. In this regard, it is instructive to also consider the objects and advantages of the present invention.
It is an object of the present invention to provide novel mounting methods for fluidic inserts that improving upon the “three-dimensional” spray performance of fluidic spray devices.
It is also an object of the present invention to provide fluidic spray devices or assemblies that can provide specific types of desired “three-dimensional” sprays that have heretofore not been achievable with conventional fluidic technology.
It is a further object of the present invention to provide improved and more versatile fluidic devices are ideally designed for a wide range of service applications.
It is a still further object of the present invention to provide fluidic devices that allow a user to better direct and control the location of the areas being wetted by the sprays from such devices.
These and other objects and advantages of the present invention will become readily apparent as the invention is better understood by reference to the accompanying summary, drawings and the detailed description that follows.